Broadcast Electronics AM500A

500W AM Transmitter 

The AM 500A from BE is designed to save you money. Sure it's small, but it's also less expensive than any other major manufacturer's 500W model. The AM500A fits easily into your existing equipment rack without tying up needed floor space. It's even less expensive to ship. What's more, the AM 500A's unique power control design can meet your nighttime power requirements without expensive splitters or the need for a separate low-power transmitter. And because of this unique engineering feature, there's less audio degradation when it's time to reduce power. 

KEY FEATURES

• Exclusive, patented class E power module achieves unequaled power economy and operating efficiencies
• Operate at five user-defined power levels, as low as 5 Watts
• Performs at the highest audio quality - even at the station's lower output power 
• Front - panel plug-in power amplifier 
• Super cooling system extends transistor life up to eight times 
• Optional output network eliminates the need for external impedance matching 
• Mounts in standard 19" EIA equipment rack 
• UPS-shippable 

AM 500A Technical Specifications

RF Specs

• Output Power:
  • • Range: 5W to 550W
    • Accuracy: 2% full scale 
• Efficiency: 60% or better, 100% sinusoidal modulation of 500W carrier into 50Ω load
• VSWR: Nominal 1.3:1 at full carrier power; will operate into higher VSWR with automatic power reduction, open and short circuit protected
• Impedance: 50Ω 
• Frequency:
  • • Range: 522kHz to 1705kHz, supplied on one frequency (synthesized), as ordered; accommodate 9kHz or 10kHz channel spacing 
• Stability:±3ppm, 0 to 50°C
• RF Harmonics Suppression: Meets or exceeds FCC, DOC, and CCIR requirements, when preceded by external NRSC-1 compatible audio low pass filter(s) 
• Modulation:
  • • Type: Pulse width modulation of L+R envelope with optional integrated C-QUAM AM stereo; an RF input connector (BNC) is also provided for an external RF or stereo exciter
    • Capabilities: > 145% peak positive capability at rated nominal output power into 50Ω load
    • Carrier Shift: < 1% at 95% negative modulation at 1kHz 
• Regulatory: Meets or exceeds FCC and DOC technical requirements, meets ENG0215 safety requirements

AM Audio Specs

• Modes: Stereo (with optional stereo card), Mono L+R, Mono L, Mono R, HD with external ASi 10; not compatible with analog stereo
• Stereo (with optional stereo card):
  • • Connector Type: 3 position terminal block (2)
    • Input Level: 10dBm, ±1dB, L+R (or mono) to produce 100% L+R envelope modulation; other input levels accommodated by internal resistor selection
    • Impedance: 600Ω; inputs are balanced, transformerless, and resistive with passive RFI filtering; other impedances can be accommodated
    • Amplitude Response:±1dB, 20Hz to 10kHz
    • THD + Noise: < 2.0% at 50% single channel modulation, 50Hz to 10kHz at rated power 
    • S/N Radio: > 55dB below a reference level equivalent to 100% negative modulation of either left or right channel in a 22Hz to 30kHz bandwidth, unweighted
    • Separation: -25dB or better, 50Hz to 10kHz, at 50% single channel modulation into a 50Ω resistive load, at rated power 
    • Squarewave Overshoot: 1% or less at 400Hz, 50% single channel modulation with high frequency boost disabled
    • Squarewave Tilt: 1% or less at 40Hz, 1.5% or less at 20Hz, measured with 90% negative modulation
    • Incidental Phase Modulation: Less than 2° (0.035 radians) average, or 30dB (typical 40dB) below equivalent 100% L-R C-QUAM modulation 50Hz to 10kHz, at rated power; measured with an audio input level which generates 95% negative L+R envelope modulation at 1kHz (9.5dBm) 
• Mono:
  
  • • ConnectorType: 3 position terminal block
    • Input Level: 10dBm, ±1dB, L=R (or mono) to produce 100% L+R envelope modulation; other input levels accommodated by internal resistor selection
    • Impedance: 600Ω; inputs are balanced, transformerless, and resistive with passive RFI filtering; other impedances can be accommodated
    • Amplitude Response: ±1dB, 20Hz to 10kHz at 90% negative modulation (linear phase mode); +0.1dB -3dB, 20Hz to 10kHz at 90% negative modulation, standard configuration
    • THD+Noise: < 1.2%, 20Hz to 10kHz at rated power 
    • Intermod Dist: 1.2% or less 1:1 ratio, 1.7% or less 4:1 ratio, 60/7000Hz SMPTE standards with 85% modulation at rated power
    • S/N Radio: > 65dB below a reference level equivalent to 100% negative modulation in a 22Jz to 30kHz bandwidth, unweighted 
    • Squarewave Overshoot: 0.1% or less at 400Hz, 90% modulation (linear phase mode) 
    • Squarewave Tilt: 1% or less at 40Hz, less than 1.5% at 20Hz, 90% negative modulation

Environmental

• Temperature: 0° to 50° C
• Altitude: 10,000 ft (3,048 M) at 60Hz; 7,500 ft (2,286 M) at 50Hz 
• Humidity: 0% to 95% (non-condensing)

Electrical

• AC Input Voltage: 196-252 VAC, 50/60Hz, single phase 
• Disconnect Size: 20 A
• AC Wire Size: #12 Copper AWG, THHN
• Current Draw: 9.5 A max
• Power Consumption: 1.25kW at 125% sinusoidal modulation of 500W carrier 
• Cooling Air Requirements: 250 CFM (7.08 M3/min) 
• Heat Dissipiation: 600W maximum for 500W RF output at 125% audio tone modulation
• BTU: 2,000 BTU/H for 500W RF Output at 125% audio tone modulation
• Power Factor: > 0.75 at full load 
• Surge Protection: 275V MOV